Wireless communication systems provide for radio communication links to be arranged within the system between a plurality of user terminals. Such user terminals may be mobile and may be known as ‘mobile stations’ or ‘subscriber units.’ At least one other terminal, e.g. used in conjunction with subscriber units, may be a fixed terminal, e.g. a control terminal, base station, repeater, and/or access point. Such a system typically includes a system infrastructure which generally includes a network of various fixed terminals, which are in direct radio communication with the subscriber units. Each of the base stations operating in the system may have one or more transceivers which may, for example, serve subscriber units in a given local region or area, known as a ‘cell’ or ‘site’, by radio frequency (RF) communication. The subscriber units that are in direct communication with a particular fixed terminal are said to be served by the fixed terminal. In one example, all radio communications to and from each subscriber unit within the system are made via respective serving fixed terminals. Sites of neighboring fixed terminals in a wireless communication system may be offset from one another or may be non-overlapping or partially or fully overlapping. In another example in which subscriber units can operate in a direct mode (e.g., without having to pass through a repeater or base station), a fixed terminal such as a control terminal may provide for a mechanism to update the direct mode subscriber units with new program settings, channels, groups, etc.
Wireless communication systems may operate according to an industry standard protocol such as, for example, the Project 25 (P25) standard defined by the Association of Public Safety Communications Officials International (APCO), or other radio protocols, the TETRA standard defined by the European Telecommunication Standards Institute (ETSI), the Digital Private Mobile Radio (dPMR) standard also defined by the ETSI, or the Digital Mobile Radio (DMR) standard also defined by the ETSI. Communications in accordance with any one or more of these standards, or other standards, may take place over physical channels in accordance with one or more of a TDMA (time division multiple access), FDMA (frequency divisional multiple access), or CDMA (code division multiple access) protocol. Subscriber units in wireless communication systems such as those set forth above send user communicated speech and data, herein referred to collectively as ‘traffic information’, in accordance with the designated protocol.
Many so-called “public safety” wireless communication systems provide for group-based radio communications amongst a plurality of subscriber units such that one member of a designated group can transmit once and have that transmission received by all other members of the group substantially simultaneously. Groups are conventionally assigned based on function. For example, all members of a particular local police force may be assigned to a same group so that all members of the particular local police force can stay in contact with one another, while avoiding the random transmissions of radio users outside of the local police force.
However, situations may arise where a particular radio user may wish to subscribe or participate in more than one group. In the past, this possibility has been provided through features such as scan lists that allow a radio user to configure their radio with a set of groups in which they are interested or subscribed, and the radio then scans each of the groups for communications and, when found, tunes to and receives communications associated with one of the particular groups. Situations may arise, however, that do not allow time for a user to configure his or her radio to scan particular groups. Additionally, pre-provisioned group IDs (e.g., identifiers that may be used to differentiate groups and as destination addresses for communications directed to group members) and group aliases (e.g., alphanumeric identifiers that may be associated with respective group IDs) associated with the groups may not be generally descriptive of a particular incident being responded to or function being performed by the group of radio users, and thus a new radio user on a scene may not know what group and/or channel to tune its radio to without transmitting on each channel and/or group to discover its use, wasting channel bandwidth and preventing effective use of the channel and/or group for emergency purposes. Furthermore, changes to the radio made by the radio user are permanently stored at the radio, and do not generally allow for temporary and/or continuous changes or updates to the radio's group membership or descriptive group names by a remote entity such as a system console. Finally, in those instances where group transmissions are being recorded or stored to preserve the contents of conversations during an incident, it may become difficult to discern which radio group's have responded to a particular incident, and difficult to locate particular desired transmissions when multiple different groups are responding to a same particular incident.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.